Process for treating amylaceous substances.



UNITED STATES PATEN T OFFICE.

AUGUS'I'E IBOJJJI'N, OF SECLIN, FRANCE, AND JEAN EFFRONT, OF BRUSSELS,BELGIUM.

PROCESS FOR TREATING AMYLACEOUS SUBSTANCES.

No Drawing.

useful Improvements in Processes for Treating Amylaceous Substances, ofwhich the following is a specification.

Our invention relates to improvements in processes for treatingamylaceous substances,

slightly acid media.

and it consists in the steps hereinafter enumerated.

An object of our invention is to provide a process for treatingamylaceous substances in which use is made of liquefying enzyms ofbacterial origin.

A further object of our invention is to provide a process of the typedescribed in which the enzyms act in alkaline media or in media fromwhich the acid and other substances poisonous toward some of thebacterial enzyms are eliminated.

Other objects and advantages will appear in the following specification,and the novel features of the invention will be particularly pointed outin the appended claims.

It is well known that the cereal enzyms which are secreted by maltedvegetables such as barley, rye, maize (which are practically the onlyenzyms used in manufactures) are only efficient when acting in neutralor We have discovered that the bacterial enzyms, that is to say theenzyms produced by many kinds of bacteria, have the property ofliquefying starch only when the mediumis kept alkaline or when thesoluble constituents of the cereals which show an acid reaction havebeen eliminated.

The present process completely differs from the methods previously knownin which alkali is used in order to dissolve the starchy or nitrogenousconstituents of the raw material previously to treating it by diastase,by the fact that in these processes the mash is always saturated, or,what is more accurate, the mash is rendered slightly acid beforeSpecification of Letters Patent.

Application filed November 6, 1913.

Patented May 22, 1917.

Serial No. 799,490.

adding the aqueous solution of malted cereal, vegetable enzyms being noteflicient in alkaline media.

It is disclosed by our French Patent, No. 399,087 of 1909 that whencultivating liquefying bacteria on whole (not ground) grains of rice orof wheat, a disaggregation of these slightly acid grains takes place asthe result of the proteolytic cytases and enzyms secreted by. thesebacteria. It is also known that when allowing a solution of these enzymsto react on rice for two to four hours at a temperature varying from 40to 0., the disaggregation thus obtained facilitates the subsequentliquefaction of the starch. But when trying to operate on an industrialscale, we have met with a series of difiiculties and we have found thatthis method does not give regular results with rice and that it is notat all suitable for other grains, such as maize, even when the latterhas been previously crushes or reduced to flour.

By a systematic study of these phenomena, we have been led to theconclusion that this preliminary disaggregation lessens considerably thevalue of the spent grains (refuse or insoluble dried refuse) by auseless dissolution of varied cellulosic and nitrogenous substances, andthat this disaggregation may be dispensed with by operating incompliance with the three following conditions:

It is necessary, to use bacteria belonging to the species subtz'lis ormesenterz'cus,- to heat directly in an alkaline medium the mixture ofground grain and of liquefying enzym,to raise this mixture from thebeginning of the treatment to such a high temperature that the cytases,proteolytic enzyms and diastase of dislocation, cannot have any actionupon the cellulosic and nitrogenoua constituents of the cereals.

When operating according to the three conditions, we can treat withequal facility quantities of enzym, which considerably reduces theexpense. As an instance of the fact that smaller quantities of enzym areemployed in the present invention than were necessary in formerprocesses, as for instance, the French Patent, No. 399,087, cited, wemay state that where one thousand pounds of grain are treated it wasnecessary to employ one hundred to two hundred gallons of enzymaticliquid in order to obtain only a pasty and thick mash in the Frenchpatent, cited, whereasby the present process we now obtain a very fullmash by using only from ten to twelve gallons of enzymatic liquid forthe liquefaction of one thousand pounds of grain. tain such good andregular results, we cultivate the species selected by those whichfurnish large quantities of starch liquefying enzym, and we have foundthat the best kinds of bacteria belong to those of the spe ciessubtilz's and mesenter-icus'which may live in an alkaline or neutralmedium, and which form thickveils and rapidly develop when growing atthe surface of nutrient media.

By cultivating many different bacteria of the common kinds belonging tothese two species in highly nitrogenized media, rich in casein or amids,and containing only small quantities ofamylaceous substances, theliquefying power of the enzyms produced is raised and this liquefyingpower becomes gradually greater and greater as new cultures are made,under favorable conditions with a more rapid reproduction of themicrobes. We thus impart by a kind of acclimatization an extraordinaryliquefying power to vulgar species and then these are renderedutilizable for industrial purposes.

The maximum liquefying power is obtained under the following conditions:

1. Repeated cultures of the bacteria on raw material stronglynitrogenized and relatively poor in carbohydrates.

2. Cultivation on large surfaces, in thin layers and in presence of anexcess of air at the commencement, and a diminution of the quantity ofoxygen afforded to the bacteria as soon as the latter are completelydeveloped.

3. If our bacteria are sown in a liquid wort and large quantities of airare passed through this wort only an insignificant quantity of bacteriaand of liquefying enzyms is produced, and the liquid becomes slightlyacid. The life of the microbe is quite different when it grows in films.It then produces large quantities of liquefying enzyms and the wortbecomes alkaline and the enzyms thus produced are able to dissolvestarch in alkaline media.

In order to ob- 'erably lessened but a saccharifyin 4. The culture is tobe made between 25 and 40 C.; the quantityof liquefying enmedium isricher in assimilable nitrogenm1s-.,

substances. All the raw materials Much only contain one part of nitrogento 35 to 15 parts of carbohydrates give solutions of feeble activity andin which the secretion of the enzyms is very slow. On the other hand theraw materials which contain one part of nitrogen to 10 to 15 parts ofcarbohydrates yield solutions very rich in enzyms. Among these lattermay be mentioned vegetable or animal albumins, the caseins, maizefibrin,boiled yeast, soja and especially soja cake.

The enzymatic liquid once produced, may be preserved for several monthsby the addition of 10 to 15 per cent. of salt or of 4 to 10 grams offormalin per liter of enzymatic liquid. The enzyms may be precipitatedfrom the solution by salts, such as sulfate of ammonia, for example, orevaporated in vacuum.

By complying'with the conditions above explained, we get solutionsshowing a great liquefying power on starch. When it is required toproduce saccharification instead of a simple liquefaction it isnecessary to promote in the bacterial culture a very intensesaccharifying power. We increase the saccharifying power ofbacterialcultnres in the proportion of 1 to 50 by operating as followsWhen our cultures have reached their maximum liquefying power, we add 8to 15 per cent. of common salt (or other salts such, for example, assulfate of soda) then nitrogeneous raw material, as soj a cake, forinstance, in such quantity that the whole forms a thick paste and thewhole is left during 24 hours at the least, at about 30 0., care beingtaken to prevent as much as possible the contact of the air. 'By thismeans the liquefying power will be considower comparable to that of awell malte l arley is produced.

In order to simplify the description of our method of utilizingliquefying enzyms of bacterial origin, we give below two examples of theoperative methods which can be followed for the treatment of .rawmaterials used in distilleries.

First example.

One thousand pounds of finely ground maize are heated between 75 and 85C., with 450 gallons of water. There is then added 6 to 10 pounds ofdried carbonate of the mixture.

soda, or of any other chemical compound capable of producing an alkalinereaction in We add then to this mixture a small quantity of liquefyingenzymatic liquid (12 to 20 gallons) and the liquefaction is effected ina few minutes. As soon as the mash becomes quite liquid, it isneutralized with any suitable acid, such as hydrochloric acid, thenheated at about 100 or 120 (1, to insure the dissolution of any starchgranules which may not have been liquefied owing to imperfect crushing.It is sufficient to treat the mash thus prepared either with a decoctionof malt employed in small quantity, or with fungi as in our U. S.Patent, No. 621,796 (1899), or any other source ofenzyms, and afterwardby the yeast in order to produce mashes or worts completely free fromstarch after fermentation, furnishing a maximum yield in alcohol and inspent grains or insoluble dried refuse.

We say that we employ reduced quantities of malt because if in theordinary process it is customary to employ 10 per cent. of a given malt,it will be sufiicient to employ 2 to 3 per cent. of this same malt. tothoroughly saccharify the starchy materials already liquefied by ourbacterial enzyms prepared as above described.

We can'also dispense with the malt and replace it by a saccharifyinculture obtained as above described an employed in a very smallquantity.

Instead of directlyefi'ecting the liquefaction of the maize or othercereal ground in a dry state, it has been found preferable to steep thecereal before crushing it, the loss due to the production of dust duringthe crushing operation is thus avoided and we thus effectually destroywith a reduced expense of motive power the horny parts of the grain, andwe more effectually set free the starch granules without reducing thebran to flour.

This preliminary steeping can be effected in various ways, either incold or hot water, and with a quantity of water necessary to increasethe weight of the grain from 25 to 30 per cent., or with an excess ofwater. It is preferable to effect the soaking with an excess of waterand under .heat because we can then eliminate after steeping theremaining water containing the extractive constituents of the grain. Wehave ascertained that this aqueous extract paralyses the action of ourbacterial enzyms. This elimination permits, at the same time, thereduction of the proportion of alkali to be employed for theliquefaction and the proportlonof enzyms, and, what is more, as theresidual water set apart is acid, it can be added to the mash as soon asthe liquefaction is produced, in order to neutralize the alkalipreviously employed.

By maintaining the mixture of water and grain at about to 75 C., duringthe soaking, we have further the advantage of precipitating thenitrogenous substances and those of the phosphates which may be modifiedby the heat. The albuminous substances being rendered insoluble, they dono longer precipitate the enzyms, and the phosphates having beendissociated in the state of insoluble polybasic phosphates of Berthelot,which remain in the insoluble parts of the cereal and in the state ofacid phosphate which pass into the liquid, the quantity of alkali to beused becomes far smaller. When working with ver hard waters, theaddition of alkali may ecome optional, because the grain has'beenrendered alkaline during the soaking. Moreover even in this latter casea slight addition of alkali is always advantageous in order to getrapidly a very fluid mash.

The soaking under heat can be effected on either whole or crushed grain.It has been found preferable to effect it on whole grain for thequantity of glucose which is found at the end of the stee ing is as muchgreater as the grain is more ely ground; ex., thus by putting into afirst receiver 100 grains of finely ground maize and 200 grams of waterand into another receiver 100 grams of whole maize and 200 grams ofwater, we have found after twelve hours at 65 to 67 (3., 7.6 grams ofglucose in the liquid of the first receiver, and 2.2 grams in that ofthe second. As this sugar is rapidly destroyed by the heat in thecooker, it is advisable to steep in whole grain.

Consequently we have been led to adopt the following mode of treatment:

Second eaaample.

One thousand pounds of unground maize or other amylaceous substances aresteeped, during 4 to 12 hours at about 70 to 80 (1., in about 300 to 450gallons or more of water. After the separation of the water, which maybe renewed one or several times (methodical diffusion), we crush the rawmaterial by means of grinding mills or cylinders. The flour is deliveredinto water maintained at about 80 C., and a small quantity of carbonateof soda, 2 to 4 pounds at themost, and 5 to 10 gallons of bacterialenzymatic liquid are added.

The liquefaction being obtained, we neutralize by addition of anysuitable acid, either mineral or organic, or by addition of steepingwater or spent wash and we proceed in the manner above described.

It is to be noted that if we roceed by a preliminary soaking and if we ten suppress the temporary elimination of the steeping Water it isnecessary in order to obtain a good liquefaction, to use at least asmuch alkali as in the first example.

Among the advantages obtained by the present processes, we may mention:

A shortened cooking and economy of coal.

Increase of the yield in spirits due to the non-destruction of the sugarpre-existing in the grain, these sugars (glucose and levulose) becomingeasily unfermentable by heating in the cooker (or converter).

Increase in the quantity of spirit arising from the fact that beforefermentation a more complete solubilization and saccharification of thestarch takes place and because there is no trace of starch remaining inthe spent grain.

Reduction of the quantity of malt,

Increase in the value of residue (or spent grain) due to a highercontent in fatty constituents and because the oil remains undecomposed,that. is to say it is not converted into soap and finally the oil ispaler and consequently more marketable.

By the shortened cooking a considerable improvement of the taste of thealcohol is obtained on account of the non-formation of nitrogenizedresins. The alcohol has a still better taste because the initial mashesare less acid than those obtained by cooking at high pressure.

The liquid spent wash is more digestible and more appetizing for thecattle and the" solid and dried spent grain has a greater nutntrvevalue, because 1t is rlcher in carbohydrates as 1n ass1m1lab1e andnon-fermentable gums.

In order to get good results by using liquefying enzyms of bacterialorigin (which are much more powerful than vegetable en-- zyms of themalted cereals), it is convenient to effect the steeping under suchconditions that the mass of grain becomes hydrated everywhere with thesame rapidity in order that the grinding may be as perfect as possible.

The grain is preferably soaked in warm water. This water ought to be ashot as possible without, however, reaching a temperature sufficientto-transform the starch into paste (see the table 9th edition of Maerker, page 10).

Soft or tender cereals are sufiiciently steeped when they have taken up25 to 30 per cent. of their weight of water, and for horny grain, thequantity of water to be absorbed should be between 45 to 60 per cent.

Finally, in order to obtain an equally rapid hydratation throughout themass of grain and to prevent at the same time infection in the steepingvats, it is necessary to maintain, by a constant and mechanicalcirculation of the steeping water, an equal temperature at all points ofthe mass. It is evident that if there exists at the upper part of thesteeping vat a temperature of 7 0 0., and that in the bottom thetemperature is only 45 (3., an intense butyric fermentation would soontake place and this fact would be prejudicial to the quality of thespirit.

In the-present process of liquefaction, the enzym can be used alone orthe mixture of enzym and bacteria. In carrying out our process, however,we preferably use a mixture containing the enzym and the bacteria,because it avoids the necessity of filtration and produces substantiallyas good results as Where the enzym is used alone.

The process herein described forms the subject of a French applicationfor patent, Number 461,853, filed November 7, 1912.

We claim:

1. A process of treating amylaceous substances consisting in steepingthe amylaceous substance at a temperature slightly lower than thegelatinizing point of the starch of "under the influence of a current ofair, the

supply of which is diminished when the development of the bacilli iscomplete.

, 3. A. process of treating amylaceous substances consisting in soakingthe amylaceous substance in hot water for from four to eight hours,separating the water in excess, grind ing the steeped substance in amoist condition, mixing the crushed substance with hot water to which isadded a little alkaline salt and liquefying enzyms, leaving theresulting substance to become liquid under the influence of the saidenzyms, and neutralizing the solution obtained.

4. A process of treating amylaceous substances consisting of steepin theamylaceous substance in hot water, liquefying this steeped substance inalkaline water under of liquefying enzyms transformed into saccharifying enzyms by the addition of salts and non-fermented nitrogenousraw materia 5. A process of treating amylaceous substances consisting insteeping the amylaceous substance in hot water for from four to eighthours separating the water inlexcess, liquefying this steeped substancein alkaline water,.at a temperature of at least 80 C. under the actionof bacterial enzyms and neutralizing the wort thus obtained by theaddition of spent wash or of the acid and aqueous extract obtained bythe steeping of the amylaceous substance.

In testimony, that we claim the f0rego ing as our invention we havesigned our names in presence of two'subscribing witnesses.

AUGUSTE BOIDIN.

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JEAN EFFRONT. FERMAND Josnrn LABARY, ALFRED DE SARVILLER.

